Method and device for reducing mechanical loads in a powertrain

Abstract

The invention relates to a method (300) and a device (170) for reducing mechanical loads in a powertrain (100). An electric machine (130) is provided as the drive assembly of the powertrain (100), and an inverter (110) is provided in order to output a multiphase output voltage for supplying the electric machine (130). The method (300) has the following steps: determining (320) the multiphase output voltage (UA) for operating the electric machine (130); adding (340) a specifiable voltage (VU) and the specified output voltage (UA); and outputting (350) the sum (SU) of the multiphase output voltage (UA) and the specifiable voltage (VU) in order to supply the electric machine (130).

1 . A method ( 300 ) for reducing mechanical loads in a powertrain ( 100 ), wherein an electric machine ( 130 ) is provided as the drive assembly of the powertrain ( 100 ), and an inverter ( 110 ) is provided for the output of a multi-phase output voltage for supplying the electric machine ( 130 ), the method comprising:
 determining ( 320 ) a multi-phase output voltage UA for operating the electric machine ( 130 );   adding ( 340 ) a specifiable voltage (VU) and the specified multi-phase output voltage (UA);   outputting ( 340 ) the sum (SU) of the multi-phase output voltage (UA) and the specifiable voltage (VU) for the supply of the electric machine ( 130 ).   
     
     
         2 . The method ( 300 ) as claimed in  claim 1 , wherein a fundamental frequency (GF) of the multi-phase output voltage (UA) is higher than a frequency (VF) of the specifiable voltage. 
     
     
         3 . The method ( 300 ) as claimed in  claim 1 , further comprising:
 determining a speed of rotation ( 322 ) of the powertrain ( 100 ), and specification ( 324 ) of a frequency (VF), amplitude (VA) or phase angle (VP) of the specifiable voltage (VU) in accordance with the determined speed of rotation.   
     
     
         4 . The method ( 300 ) as claimed in  claim 3 , wherein, as a frequency for the frequency (VF) of the specifiable voltage, the speed of rotation of the rotor of the electric machine ( 130 ), the speed of rotation of a drive shaft in the powertrain ( 100 ), or the speed of rotation of a drive wheel ( 150 ) in the powertrain ( 100 ) is specified. 
     
     
         5 . The method ( 300 ) as claimed in  claim 1 , further comprising:
 determining a structure-borne noise signal ( 326 ) of the powertrain ( 100 ), and specification ( 328 ) of a frequency (VF), amplitude (VA) or phase angle (VP) of the specifiable voltage (VU) in accordance with the structure-borne noise signal thus determined.   
     
     
         6 . The method ( 300 ) as claimed in  claim 5 , wherein, for the determination of the structure-borne noise signal ( 326 ), an acceleration sensor or a microphone is provided on the powertrain ( 100 ). 
     
     
         7 . The method ( 300 ) as claimed in  claim 1 , further comprising:
 determining resulting phase voltages or phase currents ( 332 ) of the electric machine ( 130 ), and specification ( 334 ) of the frequency (VF), amplitude (VA) or phase angle (VP) of the specifiable voltage (VU), in accordance with the phase voltages or phase currents thus determined.   
     
     
         8 . method ( 300 ) as claimed in  claim 7 , wherein, for the determination of the resulting phase voltages or phase currents on the electric machine ( 130 ), a voltage or current sensor is provided. 
     
     
         9 . A non-transitory machine-readable storage medium having a computer program, which configured to execute the method ( 300 ) as claimed in  claim 1 . 
     
     
         10 . (canceled) 
     
     
         11 . A device ( 170 ) for reducing mechanical loads in a powertrain ( 100 ), wherein an electric machine ( 130 ) is provided as the drive assembly of the powertrain ( 100 ), and an inverter ( 110 ) is provided for the output of a multi-phase output voltage (UA) for supplying the electric machine ( 130 ),
 wherein the device ( 170 ) is configured to determine the multi-phase output voltage (UA) for operating the electric machine ( 130 ); addition of a specifiable voltage (VU) to the determined output voltage (UA); and output of the sum (SU) of the multi-phase output voltage (UA) and the specifiable voltage (VU) for the supply of the electric machine ( 130 ), as a desired variable on the inverter ( 110 ).   
     
     
         12 . A powertrain ( 100 ) having an inverter ( 110 ), an electric machine ( 130 ) and a device ( 170 ) as claimed in  claim 11 . 
     
     
         13 . A vehicle ( 200 ) having a powertrain ( 100 ) as claimed in  claim 12 . 
     
     
         14 . The method ( 300 ) as claimed in  claim 1 , wherein a fundamental frequency (GF) of the multi-phase output voltage (UA) is higher than a frequency (VF) of the specifiable voltage and, the difference between the fundamental frequency (GF) of the multi-phase output voltage (UA) and the frequency (VF) of the specifiable voltage rises as the number of pole pairs in the electric machine ( 130 ) increases. 
     
     
         15 . The method ( 300 ) as claimed in  claim 6 , wherein the acceleration sensor or microphone is provided on the electric machine ( 130 ), on a gearbox ( 160 ) of the powertrain ( 100 ), on a drive wheel mounting, on a drive shaft, on a drive shaft bearing, on a power electronics unit, on an inverter ( 110 ), on a rectifier or on a battery ( 140 ) for the propulsion of the electric machine ( 130 ). 
     
     
         16 . method ( 300 ) as claimed in  claim 8 , wherein the voltage or current sensor is provided on the electric machine ( 130 ).